The present invention relates to a molded capsule which can be stably obtained with a thin membrane, which is superior in collapsing property but causes substantially no caking nor deformation by the change of pressure, temperature, humidity or the like and which can be useful in foods, drugs and cosmetics and is high in safety.
Molded capsules have been conventionally used in various fields such as foods, drugs and cosmetics. However, the capsule membrane has been prepared mainly by mixing a hydrated and swollen gelatin with a plasticizer and then drying the mixture. Such a capsule can be prepared relatively easily and is high in transparency and excellent in beauty. However, it has many disadvantages as follows. (1) It requires a long period for the preparation and drying of the membrane material in its production. (2) It requires strict temperature control to avoid leakage of packed suspension, formation of so-called avec sphere by mutual adhesion of capsules and deformation. (3) In the storage of capsules, a low humidity causes lowering of strength of the membrane to easily damage it by impact. (4) A high humidity, a high temperature or shortage of releasing agent causes deformation and caking. (5) If the thickness of the membrane is made thin, the strength becomes insufficient. (6) The collapse in digestive organs is slow.
On the other hand, as a method for eliminating these disadvantages of capsule membrane, JP 02-22221 A discloses a method for the preparation of a capsule improved in sliding and collapsing property by using a natural calcium material.
However, this method reduces transparency of the capsule and cannot produce a product of excellent beauty and cannot fully accomplish reduction of manufacturing period, improvement in strength and prevention of avec sphere and deformation, disadvantageously.
An object of the present invention is to eliminate disadvantages of conventional capsules as described above and to provide a molded capsule, i.e., a soft gel capsule, which can be easily and stably prepared and prevents liquid leakage and occurrence of avec sphere and deformation and is rich in membrane strength and has a high stability against changes in pressure, temperature and humidity. Further, an object of the present invention is to make the capsule membrane thin and to make the size of the capsule small and as the result to give a capsule product which can be easily dosed and is high in collapsing property and softness and can be used widely in various fields such as foods, drugs and cosmetics and is superior in safety.